Temperature determined sex threshold

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
I don't have any eggs, but am really curious to know if any successful breeders have worked out what temperature of incubation creates males and females in pancakes? I haven't been able to find out online so far. Does anyone know?
 

Tom

The Dog Trainer
10 Year Member!
Platinum Tortoise Club
Joined
Jan 9, 2010
Messages
50,435
Location (City and/or State)
Southern California
The only species that these numbers are studied and known is sulcatas. 90F will get you all female. 84F will get you all male. Over 90 and the likelihood of split scutes or other congenital defects goes way up. Under 84 and you can get defects and sometimes failure to develop. In between will get you a mix.

This info is not known for other species, but generally warmer makes more females and cooler makes more males. I bought a bunch of Burmese stars that were all incubated for female and half of them are male.

So much is not known about incubation temps...
 

Yvonne G

Old Timer
TFO Admin
10 Year Member!
Platinum Tortoise Club
Joined
Jan 23, 2008
Messages
86,055
Location (City and/or State)
Clovis, CA
I have always incubated all my tortoise eggs at 86-87F degrees. So far, from what I've learned after they grew, all have been male - Asian, Yellowfooted, leopard and box turtles...all male. This year I've hatched several with extra or split scutes, but we won't know if they're female for several years yet. I'm afraid to raise the temp any higher.
 

Tom

The Dog Trainer
10 Year Member!
Platinum Tortoise Club
Joined
Jan 9, 2010
Messages
50,435
Location (City and/or State)
Southern California
I have always incubated all my tortoise eggs at 86-87F degrees. So far, from what I've learned after they grew, all have been male - Asian, Yellowfooted, leopard and box turtles...all male. This year I've hatched several with extra or split scutes, but we won't know if they're female for several years yet. I'm afraid to raise the temp any higher.
You got split scutes at 86-87? Did you have any heat waves where room temp climbed?
 

Kleinmann_Fan

Member
5 Year Member
Joined
Apr 29, 2012
Messages
30
I've been hatching Marginata's since 2007, Horsfieldi's since 2013, and Eastern Hermann's since 2014, incubating every time at 89.6, using as many as 3 different incubators.
Every tortoise old enough to be sexed so far has been female.
Regarding deformities/split scutes, I've had one tiny Marginata hatch in 2012, with a massive egg sack, fewer scutes than normal, didn't eat for 4 weeks, then did okay until it passed away at 6 months.
I get the odd 2 or 3 split/extra scute babies every now and then, but have noticed this tends to coincide with incubations where I struggled to maintain consistently high humidity, I normally aim for 80%.
This last season I used 2 incubators, hatched 21 Marginata's, all perfect, 5 Horsfieldi's, 2 of which had split scutes, and 5 Hermann's, also 2 of which had split scutes.
So is humidity actually a contributing factor?, are Marginata eggs less sensitive to it?

John
 

Tom

The Dog Trainer
10 Year Member!
Platinum Tortoise Club
Joined
Jan 9, 2010
Messages
50,435
Location (City and/or State)
Southern California
I've been hatching Marginata's since 2007, Horsfieldi's since 2013, and Eastern Hermann's since 2014, incubating every time at 89.6, using as many as 3 different incubators.
Every tortoise old enough to be sexed so far has been female.
Regarding deformities/split scutes, I've had one tiny Marginata hatch in 2012, with a massive egg sack, fewer scutes than normal, didn't eat for 4 weeks, then did okay until it passed away at 6 months.
I get the odd 2 or 3 split/extra scute babies every now and then, but have noticed this tends to coincide with incubations where I struggled to maintain consistently high humidity, I normally aim for 80%.
This last season I used 2 incubators, hatched 21 Marginata's, all perfect, 5 Horsfieldi's, 2 of which had split scutes, and 5 Hermann's, also 2 of which had split scutes.
So is humidity actually a contributing factor?, are Marginata eggs less sensitive to it?

John
I have long wondered if these temps we refer to for tropical species would translate over to temperate species. I certainly don't have the answers you seek, but this is interesting to me.
 

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
The only species that these numbers are studied and known is sulcatas. 90F will get you all female. 84F will get you all male. Over 90 and the likelihood of split scutes or other congenital defects goes way up. Under 84 and you can get defects and sometimes failure to develop. In between will get you a mix.

This info is not known for other species, but generally warmer makes more females and cooler makes more males. I bought a bunch of Burmese stars that were all incubated for female and half of them are male.

So much is not known about incubation temps...
Thank you that's some good facts and figures for me :)
 

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
I'm really inter
I have long wondered if these temps we refer to for tropical species would translate over to temperate species. I certainly don't have the answers you seek, but this is interesting to me.
I'm really interested to know, my books don't have info for pancakes, but testudo seem set at high temps for female, with a risk of deformity. Thanks for all the replies :)
 

Kleinmann_Fan

Member
5 Year Member
Joined
Apr 29, 2012
Messages
30
Zoey,
A friend of mine has had an adult 1.3 group of Pancakes for about 18 months, and has had eggs from all three females, and so far hatched 1 baby in 2014, and 7 more so far this year, also at the same temps I use, same 80% humidity, no diapause, with no sign of split or extra scutes so far, and only time will tell if they are females.

John
 

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
Zoey,
A friend of mine has had an adult 1.3 group of Pancakes for about 18 months, and has had eggs from all three females, and so far hatched 1 baby in 2014, and 7 more so far this year, also at the same temps I use, same 80% humidity, no diapause, with no sign of split or extra scutes so far, and only time will tell if they are females.

John
I guess if I'm patient I'll find out eventually then ;-)

Thank you!
 

Yvonne G

Old Timer
TFO Admin
10 Year Member!
Platinum Tortoise Club
Joined
Jan 23, 2008
Messages
86,055
Location (City and/or State)
Clovis, CA
I think @Will hatched quite a few pancakes while he was at the zoo. Hopefully he has a bit of insight for you.
 

X TORTOISE---MAD X

Member
5 Year Member
Joined
Jun 5, 2011
Messages
100
Location (City and/or State)
Essex England
Is split scutes an issue then? I have my Burmese brown with lots of split scutes that look like a zip down her shell. Also my smallest pancake has an extra scute too. They are too young to tell sex yet. Just wondering if anyone believes if this is just classed as deformities in tortoises? Thanks
Hey zoey I have no idea on the temperature question but intrigued to learn more also. Hope your gang are good x
 

turtlemanfla88

Active Member
Joined
Jul 2, 2014
Messages
443
My buddy hatched out some pancakes over the last couple of years. The ones that hatched out empty egg shells were found in cooler section of their pens and are looking to be males only a year old so we still have years to go. Temps was 80-82 degrees.
 

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
Is split scutes an issue then? I have my Burmese brown with lots of split scutes that look like a zip down her shell. Also my smallest pancake has an extra scute too. They are too young to tell sex yet. Just wondering if anyone believes if this is just classed as deformities in tortoises? Thanks
Hey zoey I have no idea on the temperature question but intrigued to learn more also. Hope your gang are good x
I think split scutes are classed as a deformity, often attributed to high incubation temperatures, but out of my 19 Hermann hatchlings, who were all in the same incubator at the same temperature, only about 5 had split or extra scutes and all seem healthy. It also occurs in the wild. But people generally like 'perfection', I have scoliosis so I'm not going to judge my wonky torts!!!!
 

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
My buddy hatched out some pancakes over the last couple of years. The ones that hatched out empty egg shells were found in cooler section of their pens and are looking to be males only a year old so we still have years to go. Temps was 80-82 degrees.
Interesting as most tort species seem to favour males at low temperatures, I'll have to come back to this thread in 4 years or so lol!!!
 

X TORTOISE---MAD X

Member
5 Year Member
Joined
Jun 5, 2011
Messages
100
Location (City and/or State)
Essex England
I think split scutes are classed as a deformity, often attributed to high incubation temperatures, but out of my 19 Hermann hatchlings, who were all in the same incubator at the same temperature, only about 5 had split or extra scutes and all seem healthy. It also occurs in the wild. But people generally like 'perfection', I have scoliosis so I'm not going to judge my wonky torts!!!!
Ah bless you!
I purposely picked my brown because of the way she looks and her liveliness to her siblings. Makes them all the more special to me. I'm not a perfectionist ☺
 

tortadise

Well-Known Member
Moderator
5 Year Member
Joined
Mar 2, 2012
Messages
9,541
Location (City and/or State)
Tropical South Texas
I've hatched both female and male pancakes. The threshold seemed to be at mid 80s. Now I just incubate them at room temperature in one of the buildings. I don't have any thermometers on the eggs though. So it's kinda invaluable to comment.

I've also hatched numerous Redfoots out of the ground in the greenhouse I have. It seems the fall-winter laid eggs develop split scutes. The spring-summer laid eggs develop split scutes as well.

Some populations of pancakes have been noted to require a diapause to be successfully hatched. Many years back I had a group that required this incubation method. They also laid much larger clutches and fewer clutches than the group I have now. So regionally it can vary too. I have no idea where each ones were collected exactly. But country or origin was Mozambique.

I would guess and place the threshold at 87 or so.
 

Zoey1969

Member
Joined
Aug 3, 2014
Messages
61
Location (City and/or State)
UK
I've hatched both female and male pancakes. The threshold seemed to be at mid 80s. Now I just incubate them at room temperature in one of the buildings. I don't have any thermometers on the eggs though. So it's kinda invaluable to comment.

I've also hatched numerous Redfoots out of the ground in the greenhouse I have. It seems the fall-winter laid eggs develop split scutes. The spring-summer laid eggs develop split scutes as well.

Some populations of pancakes have been noted to require a diapause to be successfully hatched. Many years back I had a group that required this incubation method. They also laid much larger clutches and fewer clutches than the group I have now. So regionally it can vary too. I have no idea where each ones were collected exactly. But country or origin was Mozambique.

I would guess and place the threshold at 87 or so.[

Thank you for all that information, it's really useful!
 

New Posts

Top